The Cognitive Neural Mechanism Of Internet Gaming Disorder:the Compasion With Internet Gaming Recreational Users

Evidences have linked internet gaming disorder with various cognitive deficits (inhibitory control\rewarding system\decision making). And many functional magnetic resonance imaging (fMRI) studies have found that people with internet gaming disorder (IGD) showed abnormal activation in many brain regions related to these cognitive functions, for example dorsolateral prefrontal cortex (DLPFC)\orbitofrontal cortex (OFC)\anterior cingulate cortex (ACC)\posterior cingulate cortex (PCC)\insula\striatum\parahippocampal\parietal lobe.Recently researchers have found that not all drug users were drug addics, that is to say that there still existed a part of drug users who use drug occasional but not addict in drug. Researchers called them the recreational users. Further studies have found that compared with drug recreational users, the drug addics were impaired in several key cognitive function (such as inhibitory control, the carving for drug and decision-making). And evidences from fMRI have also demonstrated this. Similarly, we have found that there also existed this part of people who played internet games without negative influence (such as lost job\health\family) results from it. They played internet games without addict to it, which called internet gaming recreational users (IGRU). So we wonder what the differences between people with IGD and IGRU? If the essential differences exist, is the reason why they were able to played internet games but do not addict to it? However, few studies have investigated the differences between them.So, the present study was aimed to assess whether IGRU showed deficits in the cognitive functions and the differences between the people with IGD and IGRU. So in this study, healthy control group (HC), IGRU and people with IGD were compared in the word-color Stroop task, card guessing task and delay discounting task while scanning with functional magnetic resonance imaging.The results come out that:In the word-color Stroop task, firstly reaction time (RT) to words whose color and meaning are incongruent is longer than that of words whose color and meaning are congruent among these three groups. This showed that there were inhibitory control processing. Consistent with previous studies, the RT of IGDs is shorter than that of HC group. And we found the abnormal activation in DLPFC, showing IGDs’ impaired inhibitory control. The two internet gaming users did not showed difference in RT. But compared with IGRU, the IGDs showed more activation in brain regions related to inhibitory control, such as DLPFC, ACC, PCC and parahippocampal. Besides, compared with HC group or IGDs, the IGRU have showed significant decreased activation in inferior frontal gyrus. This indicated that the distinct pattern of activation.In card guessing task, after losses, activated brain regions both showed no significant differences between HC group and IGDs. After wins, the activated brain region was not related to rewarding system. Besides, after losses, IGDs showed increased activation in several regions related to rewarding system, while after wins decreased activations were found in ACC, OFC, middle frontal gyrus and inferior parietal lobe.in delayed discounting task, firstly consistent with previous studies, compared with HC group, IGDs showed greater discounting rate, indicating more impulsive reaction. And we found abnormal activation between IGDs and HC group in parahippocampal, striatum and thalamus. Besides the internet gaming user groups showed no differences in discounting rate. However, we found decreased activation in ACC, lingual gurus and middle occipital gyrus.We could draw the following conclusions based on the above results in present study:Firstly, Compared with HC group, IGDs showed impaired in inhibitory control and in inter-temporal choice. However, there is no difference in rewarding system between IGDs and HC group.Secondly, the internet gaming user groups showed no difference in behavioral results, but in the word-color Stroop task and delayed discounting task, abnormal activations were found in several brain regions related to inhibitory control and inter-temporal choice. It suggested compared to IGRU, IGDs showed impaired and less efficient cognitive function in inhibitory control and inter-temporal choice.Thirdly, in the word-color Stroop task, the IGRU did displayed significant different patterns of activation (decrease in inferior frontal gyrus), suggesting they are more efficient, potentially serving as protective factor against dependence.